Method of forming soldered fusible links.



L. A. GRIMES.

METHOD 0F FORMING SOLDERED FUSIBLE LINKS.

APPLICATION HLED yuNE 30.1917.

PatentedJune 11, 1918.

LESTER A.. GEII/IES, OF ORANGE, NEW JERSEY.

IVITHOD 0F FORIVIING SOLDERED FUSIBLE LINKS.

1l,269,4tt28.

Application filed June 30, 1917.

To all 'whom t may concern.'

Be it known that I, LESTER A. GRIMES, a citizen of the United States, and a resident of Orange, in the county of Essex and State of N ew Jersey, have invented a new and Improved Method of Forming Soldered Fusile Links, of which the following is a full, clear, and exact description.

This invention relates to automatic sprinkler devices and has particular reference to the art or method of soldering together the plates or elements of lfusible links adapted for use especially in connection with automatic sprinkler heads.

Fusible links that are commonly used as a means to withstand the force acting through the tension members of automatic sprinkler heads are required to be so connected with respect to their hard metal elements that the soft solder or fusible metal employed for holding the hard metal elements together will be strong enough for its purpose to resist the coldfiow of the solder and the Vpulling apart of the link elements, and yet shall be weak enough to insure the collapse of the sprinkler heads when the temperature of the building exceeds the safety point. Among the objects of this invention therefore is to provide a system or method of soldering ,together the plates or link elements in the `making of a fusible link that will meet the practical requirements above indicated and at the same time insure uniformity o f links throughout the system- In carrying out this method I show a link of the nature covered by Letters` Patent of the United States No. 1,209,574, issued to me on the 19th day of December, 1916, but I wish it to be `understood that the method set forth herein may be employed in connection with any analogous or similar type of composite fusible links.

In order to illustrate the several steps of my improved process reference is to be had to the accompanying drawings and mechanical means shown herein, similar ref erence characters being employed throughout the several gures and of which- Figure 1 is a perspective view of a link soldered in accordance with this present method. y

Fig. 2 is a plan view of one of the elements in the form in which it is made by a stamping press or the like. i

Specicaton of Letters Patent.

Patented I une il, 19de.

serial no. 177,903.

Fig. 8 is a similar view of the same element indicating how the lateral edges and one end are tinned.

Fig. 4 is a plan View of the same link turned over showing the tin applied to the inner face thereof.

Fig. 5 shows the step in applying the tinned element to a section of a mold.

Fig. 6 illustrates the two link elements aS- sembled and held in a suitable clamp and also a tension member acting on the two elements tending to separate them endwise.

Fig. is a vertical transverse section through the link and complete mold, on the line 7-7 of Fig. 8.

Fig. 8 is a vertical longitudinal section of the same on the line 8-8 of Fig. 7 and Fig. 9 is a vertical longitudinal section of a finished link on the line 9 9 of Fig. 1.

In the method of making links and assembling them as shown herein I make reference to that type of link in which the hard metal elements are shown as two in number and substantially duplicates of each other, these plates l0 each being formed with uniformly arranged lugs and depressions, the lugs of one plate coperating with the depressions of the other plate as shown best in Figs. 7, 8 and 9 and explained fully in my previous application, it being remembered that while the main or fiat portions of the plates are spaced from each other with a film or layer of solder between them filling such space, the cooperating walls of the lugs and depressions are designed to bear directly against one another so that the endwise strain tending to separate the plates is resisted directly by hard metal contacts in the nature of shoulders, and any strain tending to overcome this resistance is counteracted by the film of tin or solder 11 between and connect ing the flat portions of the plates tending to resist such bodily separation of the plates as would'permit the shoulder portions of the plates to ride over one another. When, however, the tin or solder is melted in the intended operation of the sprinkler heads this bodily separation of the plates is permitted. From what is indicated above two conditions in the method of soldering the links are important, first that the space between the flat portions of the plates shall be uniformly and completely filled with the fusible metal, and secondly that the shoulder portions of the plates are seated snugly against'one onother under suitable strain at the time the soldering takes place.

Other practical advantages also are to be noted. The plates of each link should be so connected that all boundary linesof each plate adjacent to another plate, or in other words all joints between the plates, must be thoroughly filled or covered with fusible metal in order to insure against the admission of moisture between the plates and subsequent corrosion. Moreover in accordance with the usual practice in the attempt to thoroughly cover the joint between the plates there isan unsightly and wasteful use of solder, the solder being applied in huge and irregular masses over any or all parts of the exterior of the link. By my process, however, I insure thorough sealing of the `joint with no unnecessz-iry expenditure or waste of the solder, and at the same time I `produce a finished link that is smooth, neat and uniform. in appearance, as well as possessing maximum strength and etiiciency.

As will be noted in Figs. '3 andy il each plate is thoroughly tinned all over the inside suritace where it will be covered by the companion plate and also along the lateral edges and end adjacent to 'the companion plate, the inner surface tinning being indicated at 12 and the outer edge :and end tin--y ning at This step of tinning the plates is preparatory to the assemblage olf the plates forming the link, although the step of tinning such links is, per so, not new with me. For each plate having an eye 14 I provide a mold section, the lower section being indicated at 15 and the upper section at 16. Each section of the mold is provided with a surface con'ijvilemental to the outer surace ot `the plate 'to be held therein and the recess in the mold as shown at 17 is 4suiliciently large in length and breadth to provide for the sealing rim 1S of' solder in the finished link. The mold may be made of any suitable refractory material with which vthe solder used has little or no ailinity.

The lower plate 10 is put 1in place in the recess 17 of the base 15 of the mold and while being so held in a horizontal position, plate upward, `is heated so as `to fuse the tin and receive a `small quantity `more of solder on its upper surface if necessary to insure that enough solder will be supplied to lill the space between the `Hat portions of .the plates. The next step is to apply the other or upper plate with its tinned face downward and with its eye 'extending in the `opposite ldirection from the eye of the lower plate and then the upper mold section `16 is applied, the projections and depressions -in 'the .several mold sections insure ing a proper seating of the pla-tes therein.

It is important in this process to maintain the plates and apparatus in a substantially horizontal position in order to prevent the flow oi the tin or solder from between the plates and thereby leaving -a thin space which might be left unsupplied or unlled with solder in the finished link, it being understood that the main flow ot solder through the mold or its equivalent is intended to take place mainly around and over the meeting edges of the plates instead of between them. Pressure is now applied moderately aga-inst the upper and lower faces or' the mold, as for exampleby means of a screw 19 carried by a clamp 20, al though this pressure may be applied by a pair of pliers or other means, the apparatus being maintained at sutiicient heat to keep the solder between the plates in a soft condition. It is to be noted that each mold section has a hub- 21 projecting into the eye 14 oiC that plate which lies in such section.. The hub 21 is so 'formed as to cooperate with an abutting portion of the other section to insure the proper sealing of the link at the throat portion 22. Those portions of the mold at or around the eyes lil of the plates are notched indicated at 23`so as to expose all oit' each eye except the `inner end thereof into which the hub 21 projects.

As suggested in Figs. 6 and 7 the molds may be made of any suitable length so that a series ot links `may be made at the same time by the same apparatus. My process, however, has to do mainly with the idea of employment of any suitable means for the formation of at least one link.

W'lhile the mold is held under moderate pressure by means of the clamp or pliers and with the solder between the plates in sott condition tension is applied to the 0pposite ends of the links by any suitable means, such means being indicated in Fig.` 6 as comprisin-gaspiral spring 24 havingend arms 25 sprung into eyes 14 of the plates, such tension being zsullicient to snugly seat the hard metal shoulder portions of the plates in direct `contact with one another, but separation however of the plates "is prevented by the temporary clamp. After tension is thus applied endwise Aof the plates the clamping means is made more secure or the screw if used is tightened so as to thoroughly set the two plates with respect to each other and the solder between the flat l portions thereof. With the parts in this condition the main body of solder is introduced through the funnel 26 formed on or associated with the upper section 16 of 'the mold, the solder in fluid condition running freely around the meeting .edges of the plates forming the bead. A vent 27 may be provided atany convenient `plate upon or in connection with the upper section of the mold. Both mold sections `furthermore `are provided with depressions opposite the lobe portions 28 of the plates whereby at each of the four corners of the link there will be formed a slight lump or enlargement of solder adapted to carry an imprint to indicate the maker of the link or any other suitable legend may be impressed thereon either simultaneously with or subsequent to the making of the link. The molten solder, however, poured into the funnel 26 will suiiice to fill the interstices within the mold or between the mold walls and the link elements. After supplying the solder in this manner the mold and contents will be cooled either by plunging into a cool Huid or by setting aside for a sulieient length of time. It will thus be seen that by this method of soldering links they are uniformly united and each is subjected to a proper degree of tension longitudinally while being soldered.

I claim:

l. The herein described method of forming a complete soldered fusible link comprising the assemblage of the link elements together suitably supplied with tin or solder between them, applying heat and pressure to the elements to properly seat the same with respect to each other, then applying lengthwise tension to the link elements ap- Copies of this patent may be obtained for ve cents each, by addressing lthe proximating the tension required nfor the link to withstand in practice, then applying further pressure on opposite sides of the elements, and then pouring fusible metal suit` ably conned while Huid along and over the meeting edges of the link elements to thoroughly seal the joint between them all the way around, whereby when cooled the formation of the `complete link is aecomplished.

2. The herein described method of forming a soldered fusible link comprising the assemblage of the link elements together suitably supplied with tin or solder between them and along their meeting edges, applying heat, pressure and tension to the elements to properly seat the same with respect to each other according to the type of link, then applying fusible metal suitably confined while fluid along the meeting edges of the link edges to thoroughly seal the joint between them all the way around and forming a smooth uniform bead of such metal, and finally cooling the link and the attached fluid metal while the pressure upon the element is maintained, whereby when cooled the formation of the complete link is accomplished, substantially as set forth.

LESTER A. GRIMES.

Commissioner of Patente,

Washington, D. C. 

